DEVELOPMENT OF THE DEFORMATION MONITORING SYSTEM WITH WIRELESS SENSOR NETWORK AND EVALUATION OF MECHANICAL STABILITY FOR DAMAGED STONEWALLS

Abstract

Kumamoto Castle has constructed about 400 years ago, and now Cultural Affairs Agency of Japan
treats as an important historical spot. The 2016 Kumamoto Earthquake was damaged a lot of stonewalls of this
castle. Authors continue to investigate the deformation of unstable stonewalls by high accuracy laser module for
measuring distance. And these stonewalls should be monitored continuously for the evaluation of mechanical
stability, so we developed and established the wireless network system for measuring the changing angle of some
stonewalls surface in this castle. The characteristics of this system are low cost and low power consumption with
small-scale electric generation and a simple server. Authors also carried out making the simulation model and
calculation for evaluation of stonewalls stability by the distinct element method under the several conditions of
stonewall shape and interface of materials. The failure area of stonewalls and backfill are estimated by these results
of the simulation, and it is discussed that these areas should be reinforced under repair of damaged stonewalls.